Immunoproteomics profiling of blood stage Plasmodium vivax infection by high-throughput screening assays

Completed genome sequences and stage-specific transcriptomes of the intraerythrocytic developmental cycle of Plasmodium vivax offers the opportunity to profile immune responses against P. vivax infection using innovative screening approaches. To detect the immune responses to blood stage-specific proteins, we applied a protein array technology to screen the sera of vivax malaria patients. Herein, a set of genes from the P. vivax blood stage was cloned using the In-Fusion cloning method and expressed by a wheat germ cell-free system. A total of 94 open reading frames (ORFs) were cloned and 89 (95%, 89/94) proteins were expressed, which were screened with sera from P. vivax-infected patients and healthy individuals using protein arrays. A total of 18 (19.1%, 18/94) highly immunoreactive proteins were identified, including 7 well-characterized vivax vaccine candidates. The remaining 11 ORFs have not been previously described as immunologically reactive. These novel immunoproteomes of the vivax malaria blood stage will be further studied as potential vaccine candidates. In this first report, high-throughput screening assays have been applied to investigate blood stage-specific immunoproteomes from vivax malaria. These methods may be used to determine immunodominant candidate antigens from the P. vivax genome.